Manufacture of basic dyestuffs



Patented Aug; 1, i933 Q mancracrnns or BASIC DYESTUFFS Max Wyler, ManchestenEngland, assignor to Imperial ()hemical industries Limited, a Qcrporatien of Great Britain 7 1N0 Drawing. Applicationiune 24., 193,0, Serial N0. 463,569, and in 1929 Great Britain June 27,

- 7 Claims. ((11. 260-453) The dye made acco'rding to the example sepin the iorm of its hydrochloride and probably has the structural formula This invention relates tothe manufacture of dyestuffs-of the rhodainine series. Bythis invention-valuable new dyestuiis .distinguished by brightness of shade and sol- 5 ubility are made by condensing in the presence of an appropriate agent,ffe". g. sulphuric acid, the

n-2-hydroxybenz ophenone-2-carboxylic followed by esterification of the free carboxyl group. The preparation of this aminoxylenol is described in my companion application Ser. No. 463,568.

For the purpose of my invention it is not necessary that the free aminoxylenol be used. I may use, e. g.the acetyl derivative, since the acetyl group is removed by the action of the.

acid which serves as condensing agent.

The dyeings obtained by the new dyestufis are distinguished by brightness of shade, which is :particularly evident in the pigment obtained when the dyestuffs are compared with complex 7 inorganic acids, such as phosphotung'stic acid.

My invention is illustrated, but not limited, by the following example, in which the parts are by weight.

Example 23 parts 4-diethylamino-2-hydroxybenzophenone-2 -carboxylic acid hydroxybenzoylbenaoic acid) of the constitution [Mount COOH melting at 203 (1,12% parts of the above mentioned aminoxylenol and 125 parts sulphuric acid are heated for 4 hours at 140 C.

The reaction mixture is then diluted With 1000 parts water and allowed to crystallize. After crystallization is complete the product is filtered oii and dried. It is mixed with parts ethyl alcohol boiled under reflux and a current of hydrochloric acid gas passed through the liquid for several hours. The alcohol is distilledoff, the residue dissolved in 800'parts hot water, filtered and allowed to crystallize. The esterified rhodamine separates out in beautiful crystals with green reflex which dye tannin mordanted cotton a very bright bluish red.

acid,

out departing from the spirit thereof, it is to be understood that I do not limit myself to the foregoing examples or description except as indicated in the following claims.

I claim:

1. The process of producing a new dye of the rhodamine series which comprises condensing a compound of the group consisting of 2-aminom-- xylenol and its acetyl derivatives with a alkylamino 2 -hydroXybenzophenone-2- carboxylic acid and thereafter effecting esterification of the free carboxyl group of the condensate.

2. The process of producing a new dye of the rhodamine series which comprises condensing a compound of the group consisting of 2-amin0- m-e-xylenol and its acetyl derivatives with a l alkylamino 2 hydroxybenzophenone-Zcarboxylic acid and reacting the condensate with ethyl alcohol in the presence of hydrochloric acid. I

3. The process oi'producing a new dye of the rhodamine series which comprises condensing a compound of the group consisting of 2-arnino*n- 4-.xylenol and its acetyl derivative with an alacid and thereafer-efiecting esterification of the free carboxyl groups of the condensate.

4. The process of producing a new dye of the rhodamine series which comprises condensing a compound of the group consisting of, Z-aminom-4-xylenol and its acetyl derivatives witha 4- 1 alkylamino- 2 -hydroxybenZephenone- 2-carbox ylic acid of the class consisting of monoand di ethyl and monoand di-methyl amino comkylamino- 2 -hydroxybenzophenone2-carboxylic 2 pounds and reacting the condensate with ethyl alcohol in the presence" of hydrochloric acid.

5.'The process of producing a new dye of the rhodamine series which comprises condensing 23 parts of 4-diethyl-2-hydr0xy-ben2ophenone- 2-carb0xylic acid with about 12 parts of 2- amino-m-4-xyleno1, separating the condensate and reacting it with about 100 parts of ethyl alcohol under conditions adapted to effect esterifi cation.

6. A product having theprobable formula in the formof its hydrochloride I v where R equals alkyl and obtainable by condens- COOCZHE and obtainable by condensing 23 parts of 4-diethyl-amino -2 hydroxybenzophenone 2 carboxylic acid with about 12 parts of Z-aminom-4-Xy1eno1, separating the condensate and reacting it with about 100 parts of ethyl alcohol under conditions adapted to effect esterification. 

